Used Windows 7 64 bit with the GDE scan tool and everything worked as planned. USB drivers loaded fine, the computer connected to the scan tool and downloaded and uploaded the tunes without any problems.

I have a Macbook Pro with Windows 7 64 bit and installed the software the other night. It installed easily but paused as it searched for the drivers for the USB. It did find them after a couple of minutes and works great!

I would suggest that you make sure your operating system is up to date with all updates prior to installing for best results.